Arthur s



NdModel.) A. s. ATWATBR. DHYNAMO ELECTRIC MACHINE.

No. 505,184. Patented Sept. 19, 1893.

il Il! UNITED STATESV PATENT OFFICE.

ARTIIUR S. ATWATER, OF CLEVELAND, OHIO, ASSIGNOR TO THE ATWATER GENERAL ELECTRIC COMPANY, OF SAME PLACE.

DYNAMo-ELEcTRlC MACHINE.

SPECIFICATION forming part of Letters Patent No. 505,184, dated September 19, 1893.

Application filed January 16, 1893. Serial No. L5S.591. (No model.)

.T all whom it may concern:

Be it known that I, ARTHUR S. ATWATER, a

citizen of the United States, and a resident of ers skilled inthe art to which it appertains xo to make and use the same.

My invention relates to improvements in dynamo machines in which the iield coils are excited to their full power by means of a shunt circuit derived from the armature coil.

i My invention is especially designed as a completion of the dynamo, in which is elnployed the armature described in the Letters Patent No. 411,950, granted to me October 1, 1889, where I have shown a ventilated armazo ture wound with a single coil.

My invention consists in the combination and arrangement therewith of a eoinmutator and collector rings, the controlling mechanism, and the construction of details, as here- Az 5 inafter described, shown in the accompanying drawings and more specifically pointed out in the cla-im.

In the drawings Figure 1 is a side elevation of my complete dynamo. Fig. 2 is an end View 3o of the same. Fig. 3 is a plan of commutator and brushes. Fig. 4 is an enlarged View of armature partly broken away to show the construct-ion. Fig. 5 is a detail of the commutator, and Fig. 6 is a rheostat placed in the shunt 5 5 or field circuit.

' In the drawings A, is the armature; B, the

main shaft, upon Which it is placed; C, ther pole pieces; D, the field coil; E, and E, the bearings; F, the pulley; G, G', the collector 4o rings; Il, Il the commntator sections I, the commutator clamping ring; J, the com mutator brushes; K, the brush arm; L the collector brushes; M the coarse wire coil about the armature; N, the lamp circuit; O the lamps in series, and P, the shunt which excites the field circuit. It will be seen that the shunt circuit P, is derived from the positive and negative extremities ofthe armature coil, whence it proceeds to the commutator sections I, and is thence continuous through the brushes J, J, and field coil D.

In my former patent, I described the laminated and ventilated plates Q, which form the core of the armature perforated longitudinally at R. and radially stamped to form air passages S; T, being terminal plates of soft iron of similar transverse section.

In this invention, I combine the essential elements to complete a Working device with a single coil about the armature. 6o

It will be seen that both the duplex commutator, and the collector rings, are insulated from the main shaft and from one another, and the brushes engage the faces of the rings and commutator sections instead of bearing upon their peripheries, the object of which is to lessen the friction and wear of parts, the movement of the end faces being comparativelyless than that of their peripheries. This is clearly seen in Fig. 5. The brush bearings 7c should be arranged as seen to admit of Iongi` tudinal movementof the brushes. Achief advantage of this arrangement lies in the fact that the point of commutation will remain the same as long as the brushes last. The coarse Winding coil of the armature will be seen to generate the current for the lamps, and being unbroken, will, of course, be alternating, while the shunt circuit through the tine Wire and commutator will make a continuous field cir- 8o cuit, that is will not loe reversed. Increased strength is given to the shaft by the double bearings on either side of the pulley, and thereby a smaller shaft can he employed with greater bearing surface. The commutator ring I should be composed of some insulating substance, as vulcanite or liber.

At Fig. 6, Vis seen a rheostat within the field circuit. This rheostat is provided with the cut-out W whereby the current will be 9o short circuited from the rheostat, while the machine is not in use,and on starting up Will continue to cut out the rheostat until the current generated becomes normal in strength, when the magnet X. within the circuit will become sufliciently excited to raise the armature Y, which crosses the circuit at Z, and throw the rheostat within the circuit with sufficient resistance required between the field coils and coinmutator. The necessity of this device is obvious since in starting the machine there would not be suiicient current generated in the shunt circuit to excite the field to the full capacity of the rheostat. Again when from any cause the resistance in the lamp circuit is lessened the cut out will operate to relieve the resistance in the field circuit.

Having described my invention, what I claim as new, and desire to secure by Letters Patent, is-

ln a dynamo machine, the combination of a ventilated armature, a single coarse Wire coil about the armature having its terminals in Dumme collecting rings upon the main shaft, a shunt field exciting' coil connecting the terminals of the coarse wire coil and the sections of a duplex comlnutator, a field circuit having its terminals in radial brushes engagingr the said sections and a rheostat in said eld circuit provided with an automatic cutout whereby the rheostat is cut out of the circuit until a normal current has been generated, substantially as described.

ARTHUR S. ATWATER.

Witnesses:

WM. M. MONROE, JOHN T. LrsrER. 

